What does the pads at bottom side of XBee-PRO 900HP used for? Maybe I can extend something more interesting features.
which XBee 900 module are you referring to? Can you provide a picture of the pads you are asking about? The three pads on the bottom of the SMT that are in from the edge are keep out pads using in the manufacture of the module.
Hi mvut, thanks for your reply. This is my picture 
No you are NOT losing anything by NOT connecting to these. These two headers are used for different options in the product and for production within Digi. They are NOT for customer access. The customer access pins or Headers are the 20 pins available on each (10 per side) side of the radio.
OK I see. Thanks a lot.